
When waiting at a red light, an automatic car should be shifted into N (Neutral) gear. The correct usage methods for an automatic transmission are: 1. The vehicle can only be started in P (Park) or N (Neutral) gear. To shift out of P gear, the brake must be pressed. Turn on the power, press the brake, shift to N gear, and after ignition, shift to D (Drive) gear to move forward directly; 2. When switching between N, D, and 3 gears, there is no need to press the shift button. However, shifting from 3 gear to lower restricted gears requires pressing the shift button, while shifting from lower to higher gears does not; 3. Do not shift into N gear while driving to coast; 4. Never push into P gear while driving; 5. After driving, the engine must be turned off and shifted into P gear before the key can be removed.

I've thought about this many times. When driving an automatic transmission car and waiting at a red light, the most worry-free approach is to stay in D gear and keep your foot on the brake. Many cars nowadays come with an auto-hold function (AUTO HOLD). When the green 'P' light illuminates on the dashboard, you can release the brake pedal—super convenient. For exceptionally long red lights, say over a minute, shifting to N gear and engaging the handbrake gives the transmission a breather, especially in summer when running the AC reduces engine load. Some veteran drivers prefer shifting to P gear, but if rear-ended, the transmission could be totaled—not worth the risk. Remember, never zone out playing with your phone while keeping your foot on the brake in D gear; releasing it accidentally could lead to rear-ending the car in front.

As a commuter who drives an automatic transmission car every day, my experience is to handle traffic lights flexibly based on their duration. For short red lights under 30 seconds, staying in D gear with the brake pedal pressed is the most convenient, and the start-stop system will turn off the engine for better fuel efficiency. For long red lights exceeding 30 seconds, it's recommended to shift to N gear and engage the handbrake, which reduces strain on the transmission and allows your feet to relax. The auto-hold function is truly a lifesaver—just press the button at a red light to free both feet, and step on the gas to go when the light turns green, eliminating the need to shift gears. However, it's important to note that using the handbrake instead of the foot brake on slopes is safer, especially for older models without hill-start assist.

Having driven an automatic transmission for ten years, I've learned the importance of timing when shifting gears at traffic lights. For lights changing within 10 seconds, it's most reasonable to keep the car in D (Drive) while holding the brake, as frequent shifting can wear out the gear mechanism. For cars with auto start-stop, pressing the brake deeper will stop the engine, eliminating the need to shift gears. In the case of a long red light lasting two minutes, shifting to N (Neutral) and engaging the handbrake ensures smoother transmission fluid circulation and is better for the mechanical components. I remember once seeing a mechanic dismantle a transmission where the torque converter was filled with overheated and deteriorated sludge from prolonged D-gear braking. Since then, I always shift to neutral for stops exceeding 40 seconds.

Sisters driving automatic cars, remember these three mantras: short light - step on the brake, long light - pull the handbrake, slope - add N gear. Normally when waiting at lights, don't shift to P gear - if rear-ended, repairs could cost tens of thousands. New cars now have electronic handbrakes and AUTO HOLD - when waiting at lights, press the button with 'A' to light it up, and when the green handbrake icon appears on the dashboard, you can take your foot off. Touch up makeup or scroll through your phone without worry. Special reminder for BMW and Mercedes with auto start-stop: when you press the brake hard and the engine stops, don't change gears - just lightly press the accelerator at green light and it'll automatically start and go. Remember to turn off the auto start-stop in rainy days - if the engine stalls in water and automatically restarts, it could be completely ruined!


